Fixing dates serialization in course import (#27137)

common/lib/xmodule/xmodule/tests/test_xml_module.py

@@ -4,6 +4,7 @@
 
 import unittest
 from unittest.mock import Mock
+import dateutil.parser
 
 from opaque_keys.edx.locator import BlockUsageLocator, CourseLocator
 from xblock.field_data import DictFieldData
@@ -386,6 +387,7 @@ class TestSerialize(unittest.TestCase):
         assert serialize_field(['foo', 'bar']) == '["foo", "bar"]'
         assert serialize_field("2012-12-31T23:59:59Z") == '2012-12-31T23:59:59Z'
         assert serialize_field("1 day 12 hours 59 minutes 59 seconds") == '1 day 12 hours 59 minutes 59 seconds'
+        assert serialize_field(dateutil.parser.parse('2012-12-31T23:59:59Z')) == '2012-12-31T23:59:59+00:00'
 
 
 class TestDeserialize(unittest.TestCase):

common/lib/xmodule/xmodule/xml_module.py

 # lint-amnesty, pylint: disable=missing-module-docstring
+import datetime
 
 import copy
 import json
@@ -65,6 +66,10 @@ def serialize_field(value):
     """
     if isinstance(value, str):
         return value
+    elif isinstance(value, datetime.datetime):
+        if value.tzinfo is not None and value.utcoffset() is None:
+            return value.isoformat() + 'Z'
+        return value.isoformat()
 
     return json.dumps(value, cls=EdxJSONEncoder)